1. Field of Invention
The present invention relates to a projection system and an actuator thereof. More particularly, the present invention relates to an optical actuator and a projection system using the optical actuator.
2. Related Art
In the projection system, an optical actuator is applied to increase pixels and image smoothness. The projection system includes an image generating device and a projecting lens module. The image generating device can generate the image by the technology of digital micro-mirror device (DMD), three liquid crystal panels or liquid crystal on silicon (LCoS) panel. Then, the projecting lens module helps to project the image on a screen. The optical actuator is disposed between the image generating device and the projecting lens module and is reciprocatingly rotated in high-frequency so as to achieve the function of increasing the pixels and image smoothness.
As shown in FIGS. 1A and 1B, a conventional optical actuator 10 includes a base 11, a carrier 12, a reflective mirror 13, axles 14 and a driver (not shown). The reflective mirror 13 is disposed on and connected to the carrier 12. The axles 14 are disposed at opposite sides of the carrier 12. The driver can drive the carrier 12 to rotate back and forth so that the reflective mirror 13 can be rotated back and forth along the axis X. According to the axles 14, the reflective mirror 13 can swing in a high-frequency within an angle θ so that the image can be transmitted to different positions through the reflective mirror 13. Due to the persistence of vision, the images can be overlapped so as to achieve the functions of increasing pixels and image smoothness.
However, since the axles 14 is overlapped or perpendicular to the axis X, the carrier 12 and the reflective mirror 13 can only be rotated along the axis X. Thus, the generated torque can make the axles 14 be easily deformed, which affects the image quality.